PHOENIX -- A prominent Valley doctor is standing her ground following a heavy-weight war of words between her and the oft-combative governor of New Jersey.

Dr. Connie Mariano was the White House doctor for nine years, encompassing parts of both Bush administrations and the entire Clinton presidency. She was recently asked her opinion of Gov. Chris Christie’s weight problem after the popular politician appeared on The David Letterman show eating a doughnut.

“It was sad. It was sad. He was making fun of himself and I feel sorry for him,” Mariano said in a Thursday interview with 3TV. “He's a nice man. He's a very talented, smart man and he has a lot to offer and I would feel awful if something happened to him.”

After several days of back-and-forth with the potential 2016 presidential candidate, Mariano told 3TV that she hasn’t appreciated the harsh response to her observation of Christie’s “obvious” health concerns.

"I worry that [Gov. Christie] may have a heart attack, he may have a stroke,” Mariano told CNN earlier this week. “It's almost like a time bomb waiting to happen unless he addresses those issues before running for office."

Christie did not take the criticism well, firing back at the doctor from a news conference he held in New Jersey.

“If she wants to get on a plane and come here to New Jersey and ask me if she wants to examine me and review my medical history I will have a conversation with her about that,” Christie said. “Until that time she should shut up.”

“She must be a genius," the Republican governor continued sarcastically. "She should probably be the surgeon general of the United States, I suspect, because she must be a genius. I think this is - listen, this is just another hack who wants five minutes on TV."

After these comments, Mariano said Christie called her and yelled at her.

“It was essentially the tone of the press conference only louder,” she said. "It was hard to get anything across.”

“I don’t think he realized who he was talking to,” Mariano told 3TV, adding that it’s common for medical experts to weigh in on the health concerns of potential presidential candidates. “I think I'm qualified to make a comment.”

Ironically, Mariano has been a Christie supporter and identifies herself as a Republican. However, she said her future support for a potential Christie run in 2016 is damaged.

“The way he acted lately I don't think so. He wasn't very nice to me,” she said. “Politically if this is the way [he handles] stress… is this presidential? I'll have to think about that. Is this a presidential way to behave? C'mon.”